Safety attachment for punch-presses.



O. J. MACK. SAFETY ATTACHMENT FOR PUNCH PRESSES. APPLICATION FILED AUG.2G,1012.

1,1 1 3,026. Patented Oct. 6, 1914 13 i line as as S PATENT I FFICE.

CO STER J. MACK, 0F YONKERS, NEW YORK, ASSIGNOR T0 OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORZPORATION OF NEW JERSEY.

SAFETY ATTACHMENT FOR PUNCH-PRESSES.

Specification of Letters Patent.

Application filed August 26, 1912. Bel-1211110. 716,965.

Patented Oct. 6, 1914..

To all whom it may concern: 1

Be it known that LCosrne J. Mann, a citizen of the United States, residing at Yonkers, in the'county of Westchester and State of New York, have invented a new and useful Improvement in Safety Attachments for Punch-Presses, of which the following is a specification.

My invention relates to safety attachments for punch presses and similar machines.'

An object of the invention is to provide means which shall act positively to remove the opera tors hands from a position between the die plates in case the machine is operated while his hands are in such position. In the accompanying drawings which illustrate an embodiment of my invention,

' Figure l is a view showing my safety-device attached to a punch press; Fig. 2 is a vlew on a somewhat larger scale of the safety device; Figs. 3 and l ars detail views on a. still larger scale of links used in the con struction of the safety device.

In order to illustrate the principle of operation of my invention, I have shown the T same in Fig. 1 applied to a punch press. A.

It will he understood of course that the invention is applicable to a large variety of machines of this general class. The press A as herein shown comprises a frame 1 in which is journnled a shaft 2 formed with an eccentric A drive Wheel or pulley 4 is attached to the shaft 3. The material to be operated upon, such as sheet metal, is fed between the upper and lower dies 5 and 6. During each operation of the press, the shaft 2 is given one complete revolution to carry the upper die or punch downward and then return it to a position of rest. In order to properly position the material between the dies. the. operator is required to have his hands between the dies after each operation of the press. and if the machine is accidentally operated before his hands are removed, it often results in a serious accident. In order to prrrcnt such an occurrence, I have pro- \idml an attachment which operates positively to force the operators hands to a position of safety in tbe'event of the punch descending: before his hands have been withdrawn rom beneath the punch. This device is in the form of a lazy-t0ngs carrying on its opposite ends a pair of shields. The lazytougs omprises two pairs of links 7 connected by pivots S, and short links 9, pivoted to the ends of the links 7. The short links 9 are-pivotally connected at their outer ends to shields 10. Each shield 10 is in the form of a curved arm carrying at its lower end a roller 11. Rollers 12 are provided on the links 9 to hold the shields 10 in a substantially vertical position. The safety device is attached to the lower die plate by means of an angle bracket 13 having a pivotal connection with one of the-pivot pins 8. The device is attached to the upper die plate by means of a link 14 pivotally connected at its lower end to the links 7. The link 14 is provided with a vertical slot 15. Pins 16 arranged in vertical alinement extend throughthe slot. 15 and are secured to the upper d1e plate. This construction permits a vertical movement of the link 14 relative .o the die plate. A coil spring 17 preferably connected between two of the central pivot pins 8 as shown, is normally under tension. The shields 10 are preferably provided with a facing 18 of leatheror other suitable material secured in place by means of rivets 19.

The operation of the device is as follows: When the ress is in its normal osition of rest with t e upper die lifted, tie arms or shields 10 are drawn inwardly and are in position to permit the operator to place the punching material in position or to perform any other necessar operation requiring the use of his hands between the dies. When the press is operated causing the punch to descend, the link 14 is carried downward and operates the lazy-tongs to' force the arms. 10 outward in a lateral directi0n. The operators hands and arms are thereby forced to a position of safety in case they have not already been removed before the press is operated. As the upper die is lifted the pins. 16 which extend through the slot 15 are carried upward permitting the spring 17 to draw the arms 10 inward to their initial position. The purpose of this slotund-pin connection cooperatin with the spring 17, is to permit a yiel ing inward movement of the shields so that in the event of the'operator having his hands or fingers between the links 7 and 9 while the safety device is extended the will not be pinched as the upper die .is 1i ted. In other words the arms 10 are drawn inward only with a yielding pressure due to the spring 17, whereas they are forced outwardly with a comprising relatively mov posiive iransniiiied from the descen leg ple se. The rollers 11 travel on the lower die piaie or platform during the opereiion of she sofesy device.

It will understood shat various modifications of the structure herein disclosed each other, and means to retract the lazy tongs with e yielding force as the plates are separated.

2. The combination oia punch press cornprising lower plate, an upper plate movable toward and from the lower plate, guards, a lazy tongs connecting the guards, a pivotal connection between, the lazy tongs and the lower plate, iween the lazy tongs and the upper plate, and a spring placed under tension by the extension of the lazy tongs.

3. As an article of manufacture, device comprising a lazy tongs, guards pivoted to the ends of and stop devices to limit the merit of the guards.

ll he combination of a lazy tongs, arms pivoted thereto, means to limit the rotation a safety shields or the lazy tongs, pivotal movea slot and pin connection be 7 adapted normally to take up the lost of said 21lII1$,,Ll1Cl guide rollers carried by lng across the space between said members,

a lazy tongs connecting said guards or.

shields and operable to move said guards or shields in opposite directions as one of said members is moved toward the other, and guide rollers carried by said guards or shields.

7. The combination of a machine comprising members relatively movable toward and from each other, guards or shields extending across the space between said members, a lazy tongs connecting said guards or shields and operable to move said guards or shields in opposlle directions as one of said members is moved toward the other, a lost,

motion connection between said lazy tongs and one of said members, .and a spring motion in said connection.

in .lestimony whereof, I have signed my name to this specification in the presence of two subscribing Witnesses.

COSTER J. MACK.

Witnesses 2 v J OHN E, Hronnr, EDWARD H. STEELE. 

